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Floating parks can help enhance Singapore's garden city environment
COASTAL metropolises worldwide have been dramatically transformed, especially harbour areas, as maritime industrial activities shift away to specific districts. The consolidation of Singapore's maritime infrastructure in Tuas opens up opportunities to enhance the coastal landscape with floating parks.
The development of floating parks creates new public spaces and enhances the coastal area's recreational and tourism potential. With the links between city and water progressively diminished by urbanisation over the last few years decade, floating parks could restore this relationship.
Issues associated with climate change - heat stress and rising sea levels being two problems - will impact social cohesion and public health. Floating parks could expand green spaces and improve the urban climate, biodiversity and public health. It is also a novel way of exploiting waterfronts to create new development lots.
Parks and green connectors are significant contributors to maintaining cities as liveable spaces, given their role as community spaces. Constrained by limited land banks, Singapore can tap its coastal waterfront to enhance its garden city environment.
Floating parks based on very large floating structures (VLFS) can be locally constructed with favourable unit economies and affordably maintained. Additionally, they can act as landmarks for future development; offer a platform for community and cultural events; and be a venue for showcasing innovative ideas and festivals.
It also serves as a catalyst for change, in terms of highlighting the possibilities of water infrastructure for society. A November 2018 report, "Building Urban Resilience with Nature", published by The 100 resilient Cities (Rockefeller Foundation), observes: "Nature and nature-based infrastructure are becoming recognised as a necessity for many cities. They not only meet specific service targets for water supply or flood management, but also provide a broad array of co-benefits, such as creating new parks and advancing equity and health for underserved neighbourhoods."
DRIVERS OF RESILIENCE
Nature-based solutions contribute to multiple drivers of resilience, as defined by the "City Resilience Framework". Floating parks permit further development of urban areas with limited space and high plot prices. They create free access to water for visitors through newly-built floating facilities where the waterfront is generally inaccessible. They also generate additional special function areas connected to the waterfront buildings and facilities.
VLFS constructions are mainly made of steel, like boats and pontoons. A downside of this is periodic maintenance necessary due to marine corrosion, as well as the need to produce this in a dry dock or on land. Construction cost would be high, and the dimensions of such structures would also be limited.
Using a hybrid of expanded polystyrene (EPS) and prefabricated marine concrete floor elements, floating parks can be constructed on-site with reduced vulnerability to sinking, lower maintenance costs and more favourable unit economics, especially when compared to steel/concrete structures. Besides being mobile assets, floating parks also have a lifespan of about 100 years.
With possibilities of floor areas up to 50,000 sq m, overall construction costs for floating structures using material composites are 25-30 per cent less than regular steel solutions. The comparative average costs are around 600 euros/sq m, versus 850 euros/sq m. The projected costs for floating parks would range from 3 million euros for a small, 5,000 sq m park made from hybrid materials (4.25 million euros for a steel/concrete park) to 15 million euros for a large, 25,000 sq m hybrid park (21.25 million euros for a steel park).
In short, a hybrid floating structure can be affordably built using prefabricated marine concrete elements and EPS. It can also support amenities such as shops, restaurants and hotels.
In the Netherlands, more than 70 per cent of land is below sea level. The 1953 North Sea flood emphasised the vulnerability of the country, driving the large-scale construction of dykes and pumping infrastructure to reduce the impact of future floods. However, the Dutch approach has recently shifted from "Fighting the water" to "Living with the water".
Several new projects launched during the "Room for the River" Programme - a government design plan which ran from 2006 to 2015 - were intended to address flood protection, master landscaping and the improvement of environmental conditions in areas surrounding the Netherlands' rivers.
One idea was maintaining water retention areas - where water is stored during heavy rainfall - to be sited in existing locations like old harbour facilities and farmland. The waterlogged state of water retention areas means floating structures can make these areas productive. This use of water space has seen floating houses, greenhouses and pavilions being constructed, and this Dutch strategy for water infrastructure management can be adapted to Singapore.
For instance, Singapore's iconic Gardens by the Bay and the coastal parts of Labrador Nature Reserve could be extended into the sea via floating structures. These could facilitate the growth of seagrasses, corals and mangroves. Other dividends come in the form of augmenting carbon sequestration and the expansion of urban green spaces, with their attendant community and public health benefits. In Punggol, the Housing & Development Board has built floating wetlands and planted mangroves that have enhanced the liveability of the district, as well as local biodiversity.
Generally, on a square meter area basis, the cost of building on water is considerably lower than building on land, but this depends on the design of the floating structure. They can be 10-15 per cent higher in cost than comparable land-based developments due to additional sub-structures such as access bridges, flexible cable connections and mooring facilities. On a unit area basis, given an analogous need for space in that specific area, project costs in the Netherlands were in many cases comparable to other major urban centres in Europe.
SOCIAL AND ECONOMIC VALUE
Floating parks offer tangible market and intangible non-market benefits, with social and economic value that should be accounted for by policymakers. Many fail to factor in non-market values, due to the greater difficulty in calculating their benefits. This perpetuates a prevailing bias towards land-based infrastructure as the only viable solution to urban problems.
Water management infrastructure is crucial in mitigating the worst effects of flooding and rising sea levels, especially in a city environment like Singapore. For instance, during torrential rainfall, Singapore has to store the water for a short period prior to it being drained into the sea.
Exploring the feasibility of a floating park project in Singapore requires the buy-in of legislators, policymakers and other stakeholders grappling with issues of strategy, policy and urban management across a number of domains. Questions also arise over who benefits from the building of such parks.
Floating park developments are already being explored in the United Kingdom in cities such as London and Liverpool to revitalise old harbour districts. Elsewhere, cities as diverse as Hamburg and Bangkok are also looking into developing floating parks.
As coastal and riverine waterfronts worldwide grow amid global maritime consolidation and industrial activities shift away from old harbour districts, there is immense potential for redevelopment, as well as prospects for iconic projects. Formerly industrial waterfronts can be redeveloped to integrate floating green spaces.
In fact, the global market share for large-scale floating solutions in the green and hospitality space could grow more than 50 per cent in the next three to five years, due to their unique selling points, as well as advantages in design freedom, price and maintenance.
Direct competitors of concrete composite structures are steel pontoon manufacturers, but their issue is the use of steel, which raises cost and maintenance concerns. Indirect competitors are producers of existing steel barges, as well as ships which are sold second-hand and refurbished.
My experience with Dutch authorities, as well as other nations, on floating structures highlights one key challenge - a gap that's largely administrative in nature, that of development permits and regulations governing floating structures. If Singapore and other nations are to see the emergence of floating parks, engaging and collaborating with the authorities on the relevant regulations would be key.
Singapore desires to enhance its liveability and tourism potential, as well as balance competing development needs. Floating parks can enable this, as well as offer a new business line for the maritime sector.
- The writer is CEO of Flexbase and a principal of a Dutch consortium, Holland Floating Solutions.